IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 5, Issue 3 (Sep. - Oct. 2013), PP 59-61 www.iosrjournals.org www.iosrjournals.org 59 | Page Effect of Age of Spawned Catfish (Clarias Gariepinus) Broodstock on Quantity of Eggs and Milt Produced and Growth Performance of Fry Jokthan G. E National Open University of Nigeria, Abstract: A study was conducted to determine the effect of age of catfish (Clarias gariepinus) broodstock on quantity of eggs and milt produced and subsequent growth of fry. Six ponds were used to stocked with different ages of male and female broodstock which varied from 12 to 30 months. A completely randomized design (CRD) was used. A total of thirty six male and female broodstock each were used. There were four replicates per treatment. Spawning was induced by the use of ovaprim ® injection. The eggs were fertilized with milt collected from the male broodstock. The quantities of eggs and milt produced, eggs hatched and raised to fry stage were monitored. A proximate analysis of the feed indicated that Artemia contained 55.27% crud protein and 27. 12% Nitrogen Free Extract, while Dizengoff had 57.06 crude protein and 12.61% Nitrogen Free Extract. The content of crude fibre was 4.01 and 0.90% for Artemia and Dizengoff repectively. Result showed that age of female catfish broodstock positively affected the number of eggs produced with 24 and 30 months old broodstock producing 260 and 300g of eggs respectively, while 15 and 18 months old had 150 and 160g of eggs respectively. Hatchability also increased with age of broodstock. The older the female, the higher the egg hatchability. Fry obtained from 24 and 30 months old broodstock had a significantly (p<0.05) higher weight (18g and 24g) at four weeks of age compared to fry obtained from 15 and 18 months old female broodstock which weighed 8.33g and 10.00g respectively. In order to obtain good egg number, high hatchability and optimum performance of the fry it is recommended that broodstock should be at least 24 months of age before being used for breeding. Keywords: Clarias gariepinus, Age of broodstock, performance. I. Introduction: Fish farming is a fast emerging enterprise with lots of potentials in a developing country like Nigeria. Apart from empowering the people in terms of employment, it is also a source of good quality animal protein in the diet (Jokthan, 2010). Fish meat is lean, low in cholesterol and is also regarded as a safe source of animal protein particularly since the last incidence of bird flu in the Nigerian poultry industry (Bolorunduro et al. 2001). The aquaculture sector is environmentally friendly with relatively low incidence of disease outbreak. Omole et al. (2006), reported that fish meat is non zoonotic. In order to meet its full potential, the fish production enterprise calls for distinct attention in the area of hatchery operations. The quality of broodstock affects to a very large extent the quality of fingerlings sold to farmers and the subsequent performance of the fingerings at the farmer’s level. Operations of the hatchery if well understood and exploited would serve as the bedrock of this important enterprise. It is therefore, necessary to intensify research on the best age at which female catfish produce the optimum quantity and quality of eggs that will result in good hatchability and subsequent performance of fry with a view to increasing production efficiency and profitability for farmers. This study is aimed at evaluating the effect of age of female and male broodstock on quantity of eggs and milt produced, hatchability and growth rate of catfish fry II. Materials and Method This study was conducted at Rido village, a satellite town in Kaduna State, Nigeria. Different ages of male and female broodstock were kept separately in plastic PVC tanks. A total of thirty six male and female broodstock each were used. The broodstock were acclimatized for a period of two weeks before the commencement of the study The broodstock were kept separately to avoid violence. A gutter with a dimension of 200x50x30cm, was used for the incubation of the eggs. It was fitted with an overflow that had a screen which prevented the larvae from escaping. All the fish were fumigated with formalin (75ppm) for three hours, to prevent pathogens from being transmitted to the eggs and larvae. The females were restrained, held with a towel placed on a heir back. A thumb was used to press the abdomen moving towards the tail. The appearance of greenish eggs indicated that the female was ready for inducement. After 24 hours, the selected females were injected with ovaprin at the rate of 0.5ml/ 1kg of live weight. The females were retained in the container for about 12hours at a room